The Covr AC3900 Whole Home Wi-Fi System (Covr-3902) has been renumbered and renamed to include an artificially inflated "class" rating of AC3900. This is achieved by adding the AC2600 class rating of the 4x4 AC router and 2x2 AC1300 extender.
Covr is a router / extender system, more like NETGEAR's Orbi than Google's Wi-Fi. But unlike Orbi, Covr does not use a dedicated wireless backhaul radio to connect the router and extender. The extender's simultaneous dual-band radio does double duty for both backhaul and client connection.
The router supports MU-MIMO, has Gigabit WAN and four switched LAN ports, one USB 3.0 port and has parental control and automatic priority-based QoS. The system is said to support band-steering and "smart roaming" to automatically move devices to the best radios operating under a single SSID.
Covr is shipping now and lists for $299.99.